Scaffold



Dec. 30, 1941. A. MCINTOSH j SCAFFOLD Filed Nov. 22, 193 9 INVENTQR. dw/l'ov I I i Patented Dec. 30, 1941 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to that class of apparatus used in constructing, repairing and painting of buildings, known as scaffolds.

Such scaffolds usually consist of a pair of hooks disposed on the roof in any convenient and safe manner, each hook supporting a sheave block, from which ropes extend to another pair of blocks disposed alongside the Wall of the building.

The lower blocks are raised and lowered, relative to the upper blocks, by the ropes to adjust the. distance between the blocks and maintain the blocks when adjusted.

An object of this invention is to provide a safe and secure means for adjustably anchoring such control ropes.

A further feature is in the provision of means for positively clamping or releasing such control ropes, other than by manual operation, thus leaving the hands free to perform other duties.

Another purpose is to produce a strong, safe scaffold, including a workmens platform, adjustable in width and bearing the essential elements of control rope pedally actuated clamping means. i

These valuable objects are attained by the novel and practical construction, combination and arrangement of simple parts, hereinafter described and shown in the accompanying drawing, constituting a material component of this disclosure and in which:

Figure 1 is a partial perspective view of an embodiment of the invention.

Figure 2 is an end elevational view of the same.

Referring in detail to the drawing, the numeral 5 designates the lower of a pair of blocks through which is woven several turns of a rope 6 connected with an upper block (not shown) and leading from such upper block is a control rope 1.

Fixed in the bottom of the block 5 is a hook 8 having an outturned beak 9, and carried in the loop of the hook is the eye In at the apex of a triangular frame ll, its lower element l2 being horizontal.

Disposed on the bar element i2 is a platform composed of one or more planks l5, which it is to be understood extend to a mating triangle frame near the opposite end of the platform.

A flat metallic bar I6 is disposed crosswise over the platform and is preferably secured to each of the planks I5 by bolts ll; in addition@ hooks I8 are adjustable in slots l9 near the ends of the bars, these hooks being provided with nuts 20 by which they may be drawn tightly,

against the underside of the outer planks.

Mounted midway of the bars l6, on their upper surfaces, are brackets 2|, having, in their upright'members, recesses 22 upwardly inclined at their inner closed ends and adapted to receive the rope I freely therein, the rope entering the recess at one side of the bracket and leaving at the opposite side, as clearly shown in Figure 1.

Also secured to the bars l6, spaced from the brackets, are other brackets 23 in which are fixed pivot pins 24, to act as fulcrums for levers 25.

The outer ends of these levers are fashioned as pedals 26, While the opposite, forward ends are raised and formed with curved arms 21 adapted to move closely adjacent the flat sides of the brackets 2| and clamp a rope passed through the recesses 22.

The arrangement is clearly shown in Figure 1, in which the control rope I is knotted around the beak 9 of the hook, passed through the recess 22 to be clamped by the lever arm 21, and then extended through an opening in the platform or over its side as may be convenient.

When the platform has been adjusted to the. desired height, by the control ropes 1, it is clamped by the lever and held securely by pressure on the pedal 26, and obviously released when desired.

Having thus described the invention what is claimed as new and sought to be secured by Letters Patent, is:

In an adjustable scaffold having a platform, bars secured transversely thereon, pulley blocks carrying triangular frames to support the platform, control ropes for adjusting said blocks, upright brackets on said bars, said brackets having ,rope receiving recesses, and foot actuable levers pivoted on said bars adapted to clamp a rope in the recesses of said brackets said levers closely adjacent the platform.

ALEXANDER MCINTOSH 

